There is provided a coordinates input apparatus for detecting the coordinates of a point indicated by an instruction pen on a vibration transmitting plate made of a transparent tablet on the basis of the vibration transmission times on this plate. This apparatus comprises: a pen as vibration generating means for generating a vibration; a tablet as a vibration transmitting plate to transmit the vibration generated by the pen; vibration sensors which are arranged on the tablet and detect at a plurality of positions the vibrations transmitted by making the pen come into contact with the tablet; a microcomputer for obtaining the vibration transmission distances from the vibration transmission times of the vibrations detected by the sensors and for calculating the coordinate point on the tablet with which the pen is come into contact; an output device to output the coordinate point calculated by the microcomputer; an erroneous detection discriminating circuit to discriminate whether the coordinate point calculated is the erroneously detected coordinate point or not; and a controller for allowing a correction point calculating means to calculate and output a correction point in place of the erroneously detected coordinate point.
